Smear samples are often required in the chemical or nuclear industry to monitor contamination of a given surface. Typically these samples are taken manually by health physics technicians wiping or smearing a piece of filter paper across a potentially contaminated surface so that contaminants are absorbed on the paper. It is critical that the area wiped be kept constant to allow proper measurement of contamination and also allow easy comparison with other samples. A typical area would be 100 square centimeters. After wiping, the filter paper is placed into a counter or is chemically analyzed to determine the level of radioactivity or chemical contamination that is picked up from the area sampled.
This technique suffers from several drawbacks. Both wiping pressure and area sampled can vary depending on the person conducting the test and the technique used. Thus, consistency from sample to sample is a problem. In addition, the person conducting the smear tests is risking exposure to radiation and possibly dangerous environments.
It is an object of the present invention to overcome the various shortcomings of the previous sampling methods by providing an apparatus that can give reliable, repeatable samples by a constant wiping pressure and smear area. It is a further object of the invention to provide an apparatus that can be used manually or remotely to sample the degree of surface contamination whether by radioactive or chemical materials.